This invention relates to novel pyrazine derivatives.
More particularly, it is concerned with pyrazine derivatives having the formula ##STR1## wherein X represents a hydrogen atom, a halogen atom, a lower alkyl group, a lower alkoxy group or a di-lower alkylamino group, R.sup.1 represents a hydrogen atom or a lower alkyl group and R.sup.2 represents a lower alkyl group, a benzyl group, a substituted benzyl group having as the substituent a lower alkyl group, a lower alkoxy group or a methylenedioxy group, a thienylmethyl group or a substituted thienylmethyl group having as the substituent a lower alkyl group, a lower alkoxy group or a methylenedioxy group.
The pyrazine derivatives (I) possess a potent platelet aggregation-inhibiting activity. Therefore, they are effective for preventing diseases caused by aggregation of the platelets, that is, such diseases as myocardial infarction and thrombosis. The pyrazine derivatives (I) of the invention also have a cycloxygenase-inhibiting activity. As compounds with such activity are generally known to possess an antiinflammatory activity, the pyrazine derivatives (I) are expected to find use as the antiinflammatory agent.
2. Description of the Prior Art
There have been known various compounds which have platelet aggregation-inhibiting activities. Their activities, however, are so weak that development of drugs possessing improved effects has been desired. There is also strong need for antithrombocytic agents which will effectively prevent thrombosis such as myocardial infarction and cerebral thrombosis, which recently occupy the major rate of adult diseases.
Heretofore, a variety of pyrazine derivatives are known, such as, for example, 2,3-diphenylpyrazine described in Journal of Heterocyclic Chemistry, vol. 21, pp. 103-106. However, none of these pyrazine derivatives are known to possess a platelet aggregation-inhibiting activity.